Wired: Researchers Hacked a Model S, But Tesla's Already Released a Patch

"Two researchers have found that they could plug their laptop into a network cable behind a Model S' driver's-side dashboard, start the car with a software command, and drive it. They could also plant a remote-access Trojan on the Model S' network while they had physical access, then later remotely cut its engine while someone else was driving."

https://www.wired.com/2015/08/researchers-hacked-model-s-teslas-already/